//
//  AESCrypto.m
//  JogMobile
//
//  Created by Pedro Gonzalez on 5/26/12.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//
#import <CommonCrypto/CommonCryptor.h>
#import "AESCrypto.h"

@implementation NSData (AES256)

- (NSData *)AES256EncryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

// fetch key data
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [self length];

//See the doc: For block ciphers, the output size will always be less than or 
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
   
    
    NSString *ivs = @"9keislkdfmkq4r6v";
    NSData *iv = [ivs dataUsingEncoding:NSUTF8StringEncoding]; 
    

size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                                      keyPtr, kCCKeySizeAES256,
                                      [iv bytes] ,// NULL /* initialization vector (optional) */,
                                      [self bytes], dataLength, /* input */
                                      buffer, bufferSize, /* output */
                                      &numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
    //the returned NSData takes ownership of the buffer and will free it on deallocation
    return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}

free(buffer); //free the buffer;
return nil;
}

- (NSData *)AES256DecryptWithKey:(NSString *)key {
	// 'key' should be 32 bytes for AES256, will be null-padded otherwise
	char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
	bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
	
	// fetch key data
	[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
	
	NSUInteger dataLength = [self length];
	
	//See the doc: For block ciphers, the output size will always be less than or 
	//equal to the input size plus the size of one block.
	//That's why we need to add the size of one block here
	size_t bufferSize = dataLength + kCCBlockSizeAES128;
	void *buffer = malloc(bufferSize);
	
	size_t numBytesDecrypted = 0;
	CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                                          keyPtr, kCCKeySizeAES256,
                                          NULL /* initialization vector (optional) */,
                                          [self bytes], dataLength, /* input */
                                          buffer, bufferSize, /* output */
                                          &numBytesDecrypted);
	
	if (cryptStatus == kCCSuccess) {
		//the returned NSData takes ownership of the buffer and will free it on deallocation
		return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
	}
	
	free(buffer); //free the buffer;
	return nil;
}



@end
